Reference is now made to FIG. 1 which illustrates a prior art two-layer indium tin oxide (ITO) pattern for a capacitive touchscreen sensor. A diamond-shaped electrode pattern is commonly used. A first set of diamond-shaped sensors 12, often referred to in the art as the “Yforce” structure, are provided in a first material layer. The sensors 12 are arranged in a matrix. The sensors 12 in each column are connected to each other by a connecting member 14. The sensors 12 in adjacent columns are isolated from each other. The sensors 12 and connecting members 14 are made of a first patterned ITO layer. A second set of diamond-shaped sensors 22, often referred to in the art as the “Xsense” structure, are provided in a second material layer isolated from the first material layer. The sensors 22 are arranged in a matrix. The sensors 22 in each row are connected to each other by a connecting member 24. The sensors 22 in adjacent rows are isolated from each other. The sensors 22 and connecting members 24 are made of a second patterned ITO layer.
The matrix of the sensors 12 is interleaved with the matrix of sensors 22 in a manner where the space between a group of four diamond-shaped sensors 12 is occupied by one of the diamond-shaped sensors 22, and the space between a group of four diamond-shaped sensors 22 is occupied by one of the diamond-shaped sensors 12.
The first patterned ITO material layer including sensors 12 and connecting members 14 may be the lower layer of the capacitive sensor and the second patterned ITO material layer including sensors 22 and connecting members 24 may be the upper layer (as shown in FIG. 1), or vice versa. The first and second patterned ITO material layers are isolated from each other by an interposed insulating layer. The insulating layer, first patterned ITO material layer and second patterned ITO material layer are supported by a transparent substrate layer.
Reference is now made to FIG. 2 which illustrates a prior art single layer indium tin oxide (ITO) pattern for a capacitive touchscreen sensor. Again, a diamond-shaped electrode pattern is commonly used. A first set of diamond-shaped sensors 32, often referred to in the art as the “Yforce” structure, are provided in a first material layer. The sensors 32 are arranged in a matrix. A second set of diamond-shaped sensors 42, often referred to in the art as the “Xsense” structure, are also provided in the same first material layer. The sensors 42 are arranged in a matrix. The sensors 42 in each row are connected to each other by a connecting member 44. The sensors 42 in adjacent rows are isolated from each other. The sensors 32, sensors 42 and connecting members 44 are made of a first patterned ITO layer. The sensors 32 in each column are connected to each other by conductive bridges 34 provided in a second material layer isolated from the first material layer. The conductive bridges 44 may be made of a second patterned ITO layer, or made from any other patterned conductive material layer. The sensors 32 in adjacent columns are isolated from each other.
The matrix of the sensors 32 is interleaved with the matrix of sensors 42 in a manner where the space between a group of four diamond-shaped sensors 32 is occupied by one of the diamond-shaped sensors 42, and the space between a group of four diamond-shaped sensors 42 is occupied by one of the diamond-shaped sensors 32.
The first patterned ITO material layer including sensors 32, sensors 42 and connecting members 44 may be the lower layer of the capacitive sensor and the second patterned ITO material layer including conductive bridges 34 may be the upper layer (as shown in FIG. 2), or vice versa. The first and second patterned ITO material layers are isolated from each other by an interposed insulating layer. The insulating layer, first patterned ITO material layer and second patterned ITO material layer are supported by a transparent substrate layer.
The prior art indium tin oxide patterns described above typically overlay a display screen in a stacked configuration. Commonly, that display screen is a liquid crystal display (LCD) although other display technologies may also be used. In operation, these prior art indium tin oxide patterns can suffer from an unacceptable amount of noise captured from the underlying LCD display screen. Additionally, there is room for improvement with respect to sensitivity of the prior art indium tin oxide patterns to capacitive touches (or proximity detections).
A need accordingly exists in the art for an improved ITO pattern for capacitive touchscreen applications.